The instant invention relates to medical apparatus and more particularly to a gastroenteric feeding tube which is adapted for endoscopic placement.
Gastroenteric feeding tubes (sometimes called nasoenteric feeding tubes) have generally been found to be useful for administering feeding formulas to patients who, for various reasons, are unable to meet their normal nutritional requirements through oral intake but who nevertheless have functional gastrointestinal tracts. Generally, a gastroenteric feeding tube comprises an elongated tubular flexible main portion having distal and proximal ends and having at least one side aperture therein adjacent the distal end, and a weighted bolus on the distal end. A feeding tube of this type is generally installed in a patient so that it extends through one of the patient's nostrils, through the esophagus, into the stomach and preferably into the duodenum area of the intestines. Once a gastroenteric feeding tube has been properly installed in a patient in this manner, feeding formula can be effectively administered to the patient by passing it through the tubular main portion so that the formula passes outwardly into the patient's stomach or intestines through the aperture adjacent the distal end of the main portion. Further, once a feeding tube has been installed in a patient in this manner, the weighted bolus is utilized for maintaining the feeding tube in a properly installed position in the patient so that the distal end portion of the feeding tube is not refluxed up into the esophagus during regurgitation. In this connection, for safety reasons, it has generally been found to be essential to prevent the distal end portion of a feeding tube from passing upwardly into a patient's esophagus, since once it is in the esophagus, there is a risk that it will inadvertently pass into the patient's lungs. Further, once the distal end portion of a feeding tube passes into a patient's lungs, there is an even greater risk that feeding formula will be inadvertently introduced into the lungs, causing severe respiratory problems or even death.
It has been found that when prolonged artificial feeding is required, it is generally preferable to install a feeding tube in a patient so that the distal end portion thereof is positioned past the patient's pyloric valve in either the duodenum or the jejunum area of the patient's intestines. In this regard, it has generally been found that more nutritious feeding can be carried out when feeding formula is passed directly into a patient's intestines rather than into the patient's stomach. Further, it has been found that when a feeding tube is installed so that the distal end portion thereof is positioned past a patient's pyloric valve, the tendency of the distal end portion of the feeding tube to be refluxed up into the patient's esophagus during regurgitation is significantly reduced.
One technique which has heretofore been found to be effective for installing a feeding tube in a patient is to utilize a wire stylet which is inserted into the main lumen of the tube to add stiffness thereto so that it can be manipulated during installation procedures. However, while this technique has generally proven to be an effective method for installing a feeding tube so that the bolus portion thereof is positioned in the stomach of a patient, it has not been found to be effective for moving the bolus portion of a feeding tube past the pyloric valve of a patient and into the duodenum or jejunum area of the patient's intestines. Accordingly, heretofore it has generally been the practice to first install a feeding tube in a patient so that the bolus portion thereof is located in the patient's stomach and to then rely on the patient's own peristaltic action to move the bolus portion past the pyloric valve of the patient. However, it has often been found that when a patient requires the use of a gastroenteric feeding tube, the patient is also suffering from a loss of mobility due to illness or medication. Hence, in many cases a patient may also be suffering from impaired or loss of peristaltic action so that the patient is incapable of passing the bolus end portion of a feeding tube past his or her pyloric valve without assistance.
Recently, it has been found that endoscopic procedures can be utilized for installing gastroenteric feeding tubes in patients so that the bolus portions thereof are positioned beyond the pyloric valves of patients. In this regard, a number of relatively sophisticated fiberoptic endoscopic devices have recently been developed which can be effectively utilized for mechanically moving the distal end portions of feeding tubes past the pyloric valves of patients. More specifically, endoscopic devices have been developed which are operable with appliances having grasping or snaring forceps on the distal ends thereof which can be utilized for grasping the ends of feeding tubes to install them in patients. Unfortunately, however, it has been found that most of these endoscopic devices are extremely delicate, and that they cannot be utilized for effectively manipulating feeding tubes having any significant degrees of stiffness. On the other hand, although feeding tubes must generally be soft enough to enable them to be comfortably installed in patients, they must also have sufficient degrees of stiffness to retain them in patients and to prevent them from being inadvertently withdrawn as the endoscopic devices which are utilized for installing them in patients are removed. Accordingly, it has been found that it can often be very difficult to install conventional gastroenteric feeding tubes in patients utilizing endoscopic procedures.
While heretofore several attempts have been made to adapt feeding tubes for endoscopic placement, these attempts have generally been found to be unsuccessful. Specifically, attempts have been made to adapt feeding tubes by passing sutures through the walls of the distal end portions thereof so that the sutures can be grasped by endoscopic devices for more effectively manipulating the feeding tubes as they are installed in patients. However, it has been found that when sutures are passed through the walls of feeding tubes in this manner, they can generally easily tear out during installation procedures. Further, it has been found that when sutures are passed through the walls of the bolus portions of the feeding tubes, they produce openings therein so that the weighted elements in the bolus portions are exposed to stomach fluids. Further, it has been found that sutures which extend through the sidewalls of feeding tubes are generally less than effective, since they inherently extend from the sides of the tubes rather than the ends thereof, and as a result they cannot be utilized for axially guiding or advancing the feeding tubes to install them in patients. Other attempts have been made to adapt feeding tubes for endoscopic placement by securing rings on the distal ends thereof. However, it has been found that rings also pull out of the distal end portions of feeding tubes and that it can be difficult to disengage the forceps of endoscopic devices from rings or the like.
The instant invention provides a gastroenteric feeding tube which is effectively adapted for endoscopic placement. More specifically, the instant invention provides a gastroenteric feeding tube comprising an elongated tubular flexible main portion having a longitudinally extending lumen therein, the main portion having distal and proximal ends and having at least one side aperture therein adjacent the distal end, a weighted bolus extending in substantially aligned relation from the distal end of the main portion and terminating in a terminal end, and a flexible cord element attached to the bolus so that it extends in substantially aligned relation from the terminal end. The bolus is preferably integrally formed with the main portion of the feeding tube, and it preferably has substantially the same cross-sectional dimension and configuration as the main portion. The bolus preferably comprises a tubular wall portion which extends from the distal end of the main portion, means sealing the interior of the wall portion of the bolus from the lumen in the main portion, weighting means contained in the wall portion and an end cap for sealing the terminal end of the wall portion of the bolus. The end cap preferably has an axial bore therethrough, and the cord element preferably extends in sealed relation through the axial bore, and it includes an enlarged first end which is disposed on the inner side of the end cap to retain the cord element from passing through the bore. Further, the end cap preferably has an A Durometer Scale hardness of greater than 110 to prevent the cord element from tearing out of the end cap, and the main portion and the bolus portion of the feeding tube preferably have an A Durometer Scale hardness of between 80 and 100 to enable the feeding tube to be comfortably installed and retained in a patient.
It has been found that the feeding tube of the instant invention can be effectively installed in a patientusing endoscopic procedures. Specifically, because the feeding tube of the subject invention includes a flexible cord element which extends axially from the terminal end of the feeding tube, it can be easily manipulated utilizing an endoscopic device to install the bolus portion of the feeding tube in a position past the pyloric valve of the patient. In this regard, the flexible cord element provides a buffer between an endoscopic device and the bolus portion of a feeding tube which enables the feeding tube to be easily manipulated despite the inherent stiffness thereof. Further, since the cord element extends from the axis of the terminal end of the tube, the feeding tube can be effectively axially advanced so that it can be accurately placed and guided through the stomach and past the pyloric valve of a patient. Still further, because the bolus and main portions of the feeding tube are of substantially the same diameter, there is generally sufficient clearance in the esophagus and pyloric valve areas of a patient to easily accommodate both the bolus and an endoscopic device. Still further, because of the relative hardness of the end cap portion of the feeding tube, the cord element is not easily torn from the bolus portion.
Accordingly, it is a primary object of the instant invention to provide an effective feeding tube for endoscopic placement.
Another object of the instant invention is to provide a gastroenteric feeding tube which can be effectively manipulated with an endoscopic forcep to enable it to be installed in a patient with the bolus portion of the feeding tube positioned past the patient's pyloric valve.
A still further object of the instant invention is to provide an effective feeding tube for endoscopic placement which includes a cord element which extends from an axial position at the terminal end of the bolus portion of the feeding tube.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.